In vehicles such as, for example, a car, a lorry or also a motorcycle, ever more systems for driver support are being integrated. These include navigation devices and driver assistance systems (so-called Advanced Driver Assistance Systems-ADAS). These system can also be retrofitted in older vehicles, or taken into the vehicle by the driver, as portable devices, where they might be connected to a vehicle electronics system.
A navigation system accesses stored data of an underlying traffic network. The stored data serve, on the one hand, to map on a display of the navigation system a traffic network that is as real as possible and, on the other hand, to calculate routes or travel paths through the traffic network. On the basis of such a stored traffic network, it is possible for navigation systems to calculate particular travel paths or routes between a start point and a destination point. In addition, speed restrictions can be presented to the driver on a display or overlaid in the windscreen, or lanes of the carriageway that should be taken by the driver in order to follow the route are displayed.
One aspect of driver assistance systems is that of driver support in controlling the vehicle. A driver assistance system can alert the driver to particular features on the course ahead of the vehicle. For example, when travelling through bends and/or upon approaching intersections, the front headlights may be adjusted in order to increase the traffic safety. In other words, the driver assistance system supports the driver through “anticipatory driving”.
For these tasks, the driver assistance system requires a most probable travel path, i.e. a possible future travel path. This most probable travel path is also referred to as the “Most Probable Path (MPP). The calculation of such a future route (travel path) is effected by a horizon provider. The latter determines an expected horizon, also called an electronic horizon, along which the driver will most probably travel. The electronic horizon is determined on the basis of a traffic network that is provided, for example, by the navigation system or another map data provider.
In this case, starting from the current vehicle position within the traffic network, various travel paths in the traffic network are determined along from links (roads) and nodal points (e.g. intersections). For each possible path, probabilities are calculated, which give the probability with which the driver will select this path. These probabilities may be determined by attributes of the links or nodal points, or also on the basis of stored travel data of previous journeys. The current position is determined by known systems and methods, and thus the current MPP is calculated continuously. If a destination and a route leading to it are known by the horizon provider, for example by a connected navigation system, this route may represent the MPP, or at least greatly influence the calculation of the latter. The MPP also need not comprise the entire calculated route, but may represent only a particular stretch ahead on the route, starting from the current position.
Even if navigation systems and driver assistance systems already support the d river in controlling the vehicle, there is still a need to improve these systems.